U.S. patent application number 11/140877 was filed with the patent office on 2005-10-06 for adjustable tool station.
This patent application is currently assigned to Thomson Industries, Inc.. Invention is credited to Dalessandro, Frank, Kim, Eric, Ng, Alison.
Application Number | 20050217449 11/140877 |
Document ID | / |
Family ID | 29548278 |
Filed Date | 2005-10-06 |
United States Patent
Application |
20050217449 |
Kind Code |
A1 |
Ng, Alison ; et al. |
October 6, 2005 |
Adjustable tool station
Abstract
A miter saw includes a tool adjustment unit having a joint
pivotable about an axis, a guide rail spaced from and coupled to
the joint so as to pivot about the axis, a saw housing mounted on
the guide rail and a linear motion bearing assembly, which is
positioned between the guide rail and the saw housing. The guide
rail and the linear motion bearing are so shaped and dimensioned
that the saw housing and the guide rail rotationally engage one
another in a substantially play free manner to displace a saw blade
between a plurality of angled positions.
Inventors: |
Ng, Alison; (New York,
NY) ; Kim, Eric; (Flushing, NY) ; Dalessandro,
Frank; (Bayside, NY) |
Correspondence
Address: |
DILWORTH & BARRESE, LLP
333 EARLE OVINGTON BLVD.
UNIONDALE
NY
11553
US
|
Assignee: |
Thomson Industries, Inc.
|
Family ID: |
29548278 |
Appl. No.: |
11/140877 |
Filed: |
May 31, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11140877 |
May 31, 2005 |
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10146106 |
May 15, 2002 |
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6918330 |
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10146106 |
May 15, 2002 |
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PCT/US01/50897 |
Oct 24, 2001 |
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60242850 |
Oct 24, 2000 |
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Current U.S.
Class: |
83/581 |
Current CPC
Class: |
F16C 29/001 20130101;
Y10T 83/7697 20150401; Y10T 83/7772 20150401; Y10T 83/7726
20150401; F16C 2322/39 20130101; Y10T 83/949 20150401; Y10T 83/7705
20150401; Y10T 83/8773 20150401; F16C 29/069 20130101; Y10T 83/7788
20150401; Y10T 83/8878 20150401 |
Class at
Publication: |
083/581 |
International
Class: |
B26D 005/08 |
Claims
1-17. (canceled)
18. A saw comprising: a table having an elongated axis; a rotary
joint fixed to the table and rotatable about the elongated axis in
response to an external torque; a longitudinally extending guide
rail spaced radially from the elongated axis and fixed to the
rotary joint to pivot with respect to the elongated axis during
rotation of the rotary joint, the guide rail having an annular
cross-section and a shape selected from the group consisting of a
cross-shaped cross-section, I-beam cross-section, regular polygonal
cross-section and an irregular polygonal cross-section; a saw
housing receiving a saw blade and mounted on the guide rail; and a
linear motion bearing assembly mounted between the guide rail and
the saw housing and rotationally fixed to the housing to provide
linear displacement of the saw housing along the guide rail, the
linear motion bearing assembly and the guide rail being shaped and
dimensioned to prevent rotational movement relative to one another
during angular displacement of the saw housing between beveled
positions of the saw blade.
19. The saw as claimed in claim 18, further comprising two guard
plates mounted on the table and spaced laterally apart to define
clearance therebetween which is unblocked during displacement of
the saw housing and the guide rail between the beveled positions of
the saw blade.
20. A power hand tool comprising: an elongated guide rail pivotable
about an axis; a tool housing mounted on the guide rail; and a
linear motion bearing assembly mounted between the guide rail and
the tool housing to provide smooth linear displacement of the tool
housing along a length of the guide rail between a plurality of
axial positions of the tool housing, the guide rail and the linear
motion bearing assembly being shaped to engage one another in a
fixed rotational relationship during displacement of the tool
housing between a plurality of angled positions, the linear motion
bearing assembly having a plurality of individual rolling element
retainer segments surrounding the guide rail, the plurality of
individual rolling element retainer segments each including a
respective load bearing track portion and a respective return track
portion receiving a plurality of rolling elements which circulate
along the load bearing and return portions during displacement of
the tool housing along a length of the guide rail, and the guide
rail having an annular cross section and a shape selected from the
group consisting of a cross-shaped cross section, I-beam cross
section, regular polygonal cross-section and irregular polygonal
cross section.
21. The tool as claimed in claim 20, wherein the load bearing track
portions are spaced apart and juxtaposed with the guide rail so
that the rolling elements running along the load bearing tracks
engage the guide rail to prevent relative rotation of the saw
housing and the guide rail.
22. The tool as claimed in claim 20, wherein the return track
portions are spaced radially outwards from the load bearing track
portions.
23. The tool as claimed in claim 20, further comprising a base, a
joint mounted on the base and rotatable about the axis, and a rail
guide rail housing rigidly coupled to the joint and to the rails
guide, so that the opposite ends of the guide rail are rotationally
fixed to the tool housing and to the guide rail housing
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of
International Application No. PCT/US01/50897, filed Oct. 24, 2001,
which claims the benefit of U.S. Provisional Application
60/242,850, filed on Oct. 24, 2000.
FIELD OF THE INVENTION
[0002] The present invention relates to an adjustable tool station.
More particularly, the invention relates to a guide assembly
rotatably engaging a tool head in a substantially play-free manner
to prevent rotation of the tool head.
BACKGROUND OF THE INVENTION
[0003] Numerous power hand tools assisting a user in accomplishing
a variety of tasks are known. Generally, such tools include a base
and a tool head for performing a certain task, for example, cutting
and/or sawing a workpiece composed of wood, plastic, metal or other
various materials. Typically, a saw assembly includes a blade and
various actuators adapted to displace the blade linearly along a
longitudinal axis, rotate the blade about the longitudinal axis in
various angled or beveled positions, and/or displace the blade
along a pivot axis extending perpendicular to the longitudinal
axis.
[0004] Examples of such a saw assembly include compound miter/chop
saws allowing the user to selectively move the saw blade into any
of a number of positions for square cutting, miter cutting, bevel
cutting, or compound miter cutting where a combination miter angle
and bevel angle are cut. In addition, it is essential that the saw
blade move linearly to accommodate different lengths of the
workpiece. In order to allow for the adjustment of the miter and
the bevel angle, the saw blade, cutter or other working device can
move along a horizontal base across the workpiece. Subsequently, if
an angular adjustment of these elements is desirable, the bevel
adjustment allows the saw blade, cutter or other working device to
be positioned at an angle with respect to the horizontal base. At
times it may be desired to cut a combination miter angle and bevel
angle by simultaneously adjusting the angle of the blade with
respect to both the horizontal base and a vertical guard.
[0005] Once the saw blade, cutter or other working device has been
adjusted to the desired position with respect to the horizontal
base and the vertical fence, locking mechanisms for the miter and
bevel adjustment must be activated in order to prohibit movement of
the saw blade, cutter or other working device from the set position
with respect to the base and fence while the cutting operation is
performed. These locking mechanisms need to be easily activated,
adjustable and quick acting in order to optimize the efficiency of
the cutting apparatus and provide convenience to the operator of
the apparatus.
[0006] A typical saw assembly of the type, as discussed above, is
disclosed in U.S. Pat. Nos. 6,035,754; 5,907,987, 5,870,938; and
5,870,838. As shown in FIG. 1, sliding compound miter saw 10
disclosed in the above-mentioned patents includes a base 12, a
table 14, a housing 16, a saw blade 18, a blade guard 20, a motor
22 drivingly connected to saw blade 18, a handle 24 and a guard 26.
The table assembly 14 is secured to the base 12 such that it can be
rotated in order to provide adjustment for miter cutting. The
housing 16 is secured to the table 14 such that it can be pivoted
to adjust the angle of the saw blade 18 relative to table 14 for
bevel cutting. To provide linear movement of a saw head consisting
of the saw blade 18, the motor 22, the handle 24 and the blade
guard 20 relative the table 14, the housing 16 has two support arms
34 coupled with the saw for synchronous sliding movement. The
sliding movement of support arms 34 drives the housing 16 and the
saw blade 18 so that the saw blade can be pulled through the
workpiece when the size of the workpiece exceeds the cutting width
of the saw blade 18.
[0007] A fairly complicated combination of movements can be
inconvenient for the user operating the miter saw 10. First,
displacement of support arms 34 attached to the saw head for
synchronous linear displacement therewith to an initial position,
in which the saw blade 18 is located next to the guard 26,
increases the overall size of the saw. A portable tool design, like
the miter/chop saw discussed here, requires that such a tool be
compact.
[0008] Still another disadvantage oa the above-disclosed miter saw
may be observed during angular displacement of the saw blade
between numerous angular positions which may be accompanied by
undesired rotation of the saw head relative to the support arms. To
minimize undesired rotation, mans prior-art references including
those discussed above disclose a two-aim support and guide system.
Arms 34 can be positioned relative to one another either in a
vertical or a horizontal plane.
[0009] The vertical arrangement of the arms, as disclosed in the
cited patents, minimizes undesired rotation of a saw head until the
saw head reaches a 40-45.degree. angular position. In this
position, the upper arm supports some of the load of the saw head
and rubs against a plain bushing supporting this arm, which, in
turn, causes drag. In the horizontal arrangement, both arms always
support the load of the saw head and; thus, the drag problem
manifests itself at an angle smaller than a 45.degree. angle.
[0010] It is, therefore, desirable to provide a compact, light and
simple structure saw assembly of the type described above. Also,
the saw assembly having a structure with minimized play between a
saw head, which includes the saw blade, its housing and other parts
fixed to the blade for synchronous angular displacement therewith,
and a support and guide system is also desirable.
SUMMARY OF THE INVENTION
[0011] An improved structure of a portable power tool, such as a
miter/chop saw, having a reduced overall size and reliable
engagement between angularly displaceable parts is attained in
accordance with the present invention.
[0012] In accordance with one aspect of the invention, a saw
housing receiving a saw blade-is linearly guided along a guide
rail, which is not linearly displaceable along with the say
housing. As a consequence, the overall size of the power tool is
reduced.
[0013] Another aspect of the present invention is directed at
minimization of undesirable play between a guide rail and a saw
housing during angular displacement of the entire system. To attain
this, the guide rail is shaped to mesh with a linear motion bearing
segment which is fixed to the saw blade housing. The linear motion
bearing segment has a plurality of self-contained roller or ball
retainer segments arranged so that the bearing segment and the
guide rail engage one another in a substantially play-free manner
during pivotal displacement of the miter saw between beveled or
angled positions of a saw blade.
[0014] As a consequence, the inventive single guide rail eliminates
one shaft or arm of the support system along with a respective
plain bushing disclosed by the above-discussed prior art.
Furthermore, as a result of the bearing segment and a shape of the
guide rail preventing undesired torsional motion of structural
components relative to one another, the inventive system is
characterized by reduced drag.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The above and other objects, features and advantages will
become more readily apparent from a specific description of the
preferred embodiments accompanied by the following drawings, in
which:
[0016] FIG. 1 is a front perspective view of a sliding compound
miter/chop saw in accordance with the prior art;
[0017] FIG. 2 is a perspective view of the sliding compound
miter/chop saw in accordance with the invention and illustrated an
initial position of the meter sass;
[0018] FIG. 3A is a transverse cross-sectional view of the sliding
compound miter/chop saw taken along lines III-III of FIG. 2;
[0019] FIG. 3B is an exploded perspective view of a half bearing
segment of a linear motion bearing segment and a guide rail;
[0020] FIG. 3C is a perspective view of the assembled linear motion
bearing segment supporting the guide rail in accordance with the
present invention;
[0021] FIG. 4 is a diagrammatic cross-sectional view of an
alternate embodiment of the guide rail in accordance with the
invention.
[0022] FIG. 5 is a perspective view of the sliding compound
miter/chop saw shown in FIG. 2 and illustrated in ane extended
position of the miter saw;
[0023] FIG. 6 is a perspective view of the sliding compound
miter/chop saw shown in FIG. 2 and illustrated in an angled
position of the saw blade; and
[0024] FIG. 7 is a front elevational view of the compound
miter/chop saw shows in FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Referring now to the drawings, in which like reference
numerals designate corresponding parts throughout the several
views, FIGS. 2 and 5-7 illustrate a compound miter/chop saw 10
incorporating a support and guide assembly 30 in accordance with
the present invention.
[0026] The compound miter/chop saw 10 includes a single guide rail
40, which is mounted on the table 14 so that the guide rail 40 does
not move linearly along an axis A-A, and a saw housing 38 slidable
along the guide rail 40. Linear displacement of the saw housing 38
into a position shown in FIG. 5 along the axis A-A is necessary
when a workpiece to be sawed has a substantial size exceeding the
diameter of the saw blade 18.
[0027] The compound miter/chop saw 10 further includes a rotatable
join 48 mounted rotatably about an axis A-A on the table 14 and a
guide rail housing 68 rigidly coupled to the rotatable joint 48 by
means of an arm 66 (FIG. 6) for synchronous pivotal motion around
the axis A-A. The guide rail housing 68 receives an end 42 (FIG.
BB) of the guide rail 40 and engages it so that the guide rail
housing 68 and guide rail 40 are rotationally and linearly fixed
relative to one another. The guide rail 40, as shown in FIGS. 7-7,
has an annular shape provided with a spline 58 (FIGS. 2,3 and 5-7),
and guide rail 40 engages a recess or nest 108 (FIG. 5) which has
an inner surface formed complementary to the spline 58. The nest
108 of the guide rail housing 68 and the spline 58 engage one
another so that there is no rotational or linear displacement
between the guide rail housing 68 and the guide rail 40. Note that
any arrangement rotationally and linearly fixing the guide rail
housing 68 to the guide rail 40 can be used depending on a shape of
the guide rail 40, which, for example, can be cross-like, I-beam,
regular or irregular polygonal or annular.
[0028] Linear displacement of the saw housing 38 along the guide
rail 40 is provided by means of a linear motion bail bearing
assembly 44 (FIGS. 3A-3C), which is disclosed in a co-pending
application Ser. No. 60/242,850 and fully incorporated herein by
reference. In particular, the ball bearing assembly 44 is
fabricated from a plurality of individual arcuate interengageable
self-contained rolling element retainer segment. A cross sectional
view seen in FIG. 3A and taken along lines III-III of FIG. 2,
illustrates a combination of the rolling element bearing segment
assembly 44 mounted within a bore provided in an end 73 (FIGS. 3C
and 5) of a Z-shaped lever 70 of the saw housing 38 and
interengaged witch the guide rail 40. Two individual quarter
arcuate self-contained rolling element retainer segment 52 and a
single half arcuate self-contained ball retainer segment 54, which
constitute the bearing segment assembly 44, are supported in
interengageable association with the end 73 of the Z-shaped lever
70 of the saw housing 38. A longitudinal groove 102 (FIG. 3C) is
formed along an inner surface of the bored end 73 of the saw
housing 38 for engaging the half arcuate retainer segment 54. When
fully assembled, the quarter arcuate retainer segments 52 and the
half arcuate retainer segment 54 are adapted and configured to move
linearly smoothly on the guide rail 40, along with the saw housing
38. Note that a number of segments can vary.
[0029] The half arcuate ball retainer segment 54 includes a base
portion 63 (FIG. 3B) having an inner surface configured and adapted
to be in substantial clearance of the spline 58 formed along a
longitudinal length of the guide rail 40. The base portion 63
includes a pair of independent ball bearing tracks 80 formed
therein for retaining a plurality of rolling elements, which
includes balls or rollers 56. Each rolling element bearing track 80
is made up of a load bearing portion 57 (FIG. 3A) and a return
portion 59 interconnected by turnarounds 84 (FIG. 3B) for
recirculating the balls or rollers 56 therealong during linear
displacement of the saw housing 38 alone the guide rail 40. The
respective load bearing portions 57 are located adjacent to one
another and are spaced from one another along the base portion 63
(FIG. 3B).
[0030] The half arcuate rolling element retainer segment 54 further
includes a single load bearing plate 86 having an inner surface,
which is configured and adapted to be disposed over both load
bearing portions 57b of each ball bearing track 80, and an outer
surface defining a pair of longitudinally extending convergent flat
portions 58. Each convergent flat portion 88 is configured and
adapted to engage a respective biasing member 90, which can be any
resilient element, such as a spring. In addition, the half arcuate
ball retainer segment 54 includes a pair of lids 92 and 94 serving
to close the half arcuate ball retainer segment 54. Each lid is
provided with a window 96 aligned with one of the convergent
segment 88 and through which windows 88 the biasing members 90
extend to contact the inner surface of the end 73 of the saw
housing 38, as shown in FIG. 3C.
[0031] To displace the saw blade 18 between a plurality of beveled
or angled positions, as shown in FIG. 6, the arm 66, the guide rail
housing 68, the guide rail 40 and the saw housing 38 pivot about
the axis A-A as the rotatable joint 48 rotates about this axis
(FIG. 2). Interengagement between the guide rail 40, the linear
motion bearing segment assembly 44 and the end 73 of the Z-shaped
ever 70 of the saw housing 38 prevents undesired angular
displacement between the saw housing 38 and the guide rail 40.
[0032] In particular, as shown in FIGS. 3A-3C, the inner surface of
the end 73 of the saw housing 38 has radial ribs 104 extending into
clearances 106 which are formed between the quarter arcuate and
half arcuate retainer segments 52 and 54. Such engagement provides
fixed rotational contact between the saw housing 38 and the linear
motion bearing segment assembly 44. The half arcuate retainer
segment 54 is provided with a longitudinal recess 61 (FIG. 3B)
having an inner surface extending complementary to opposite sides
100 and 98 of the spline 58. Furthermore, the opposite sides 98 and
100 of the spline 58 are pressed upon by the balls or rollers 56
which are pre-loaded due to a force applied by the biasing members
90 through the converging flats 88 of the load bearing plate 86.
The pre-load being applied against opposite sides 98 and 100 of the
spline 58 at an angle ".theta." (FIG. 3A) selected so that the
spline 58 and the balls or rollers 56 preserve sliding contact
therebetween.
[0033] To prevent angular displacement of the linear motion bearing
segment assembly 44 and the saw housing 38 relative to the guide
rail 40, the balls or rollers 56 abut the opposite sides 98 and 100
of the spline 58 such that the guide rail 40 and the balls 56
cannot be angularly displaced independently from one another.
Particularly, the converging flats 88 of the load bearing plate 86,
the ball bearing tracks 80 of the base portion 54 and the opposite
sides 98 and 100 of the spline 58 are shaped to angularly support
the balls or rollers 56, which circulate along the parallel load
bearing portions 57, as shown in FIG. 3A. The balls or rollers 56
are this prevented from moving out of contact with the opposite
sides 98 and 100 of the spline 58 during angular displacement of
the saw housing 38 and the guide rail 40. Thus, any relative
angular motion between the balls or rollers 56 and the rail guide
40 is substantially eliminated. As shown in FIG. 3A, a retaining
member 65 above the load bearing plate 86 is placed in the recess
61 to provide additional lateral support for the balls 56 running
along both load bearing portions 57.
[0034] Note that the number of the rolling element retainer segment
and their cross-section, as well as the number of the splines can
vary depending on a load and a shape of the guide rail 400. It is
essential, however, that the guide rail 40 rotationally engage the
linear motion bearing segment assembly 44 and the saw housing 38 in
such a manner as to minimize a possibility of voluntary angular
displacement of the saw housing about the rail guide 40. Thus, for
example, FIG. 4 illustrates the guide rail 40 provided with a
plurality of cutouts 64 which are spaced circumferentially-apart
and form respective ball loading bearing tracks receiving the
rollers or balls 56 of the linear motion beating assembly 44.
Although the geometry of the guide rail 40 of FIG. 4 has a
cross-like shape, this embodiment operates in a mauler similar to
the one described immediately above.
[0035] Thus, in response to an external torque, a mechanical link
is created between the saw housing 38, the linear motion bearing
assembly 44, the guide rail 40, the guide rail housing 68, the arm
66 and the rotatable joint 48, which pivot synchronously about the
axis A-A axis in a substantially play-free manner. As a result of
the described kinematics, the housing 38 can be displaced into a
desired angled or beveled position of the blade 18 in a manner
preventing the saw housing 38 from undesired torsional motion
relative to the guide rail 40. Also, the inventive structure avoids
drag even when the saw housing 38, the guide rail 40, and the guide
rail housing 68 are displaced into a 45.degree. angled position of
the blade 18.
[0036] The Z-shaped lever 70 of the saw housing 38 (FIGS. 2, 5 and
6) positions the rail guide 40 so that the latter is laterally
offset from a vertical axis B-B of the table assembly 14 when it is
in a normal, vertical position, as shown in FIG. 7. As a result of
such a shape of the lever 70, clearance for the guard plates 26 is
always provided regardless of whether the saw housing 38 rotates
clockwise or counterclockwise.
[0037] A combination of the guide rail 40 and the bearing segment
assembly 44 can be successfully utilized in any portable power tool
provided with rotatably meshing par-s. Such a portable tool can
included, but limited to, routers, plate joiners, and different
types of drill presses, coping and dic saws. Thus, while the
invention has been particularly shown and described with reference
to the preferred embodiments, it will be understood that various
modifications and changes in form and detail may be made therein
without departing from the scope and spirit of the invention as
defined in the following claims.
* * * * *